This invention pertains to cigarette manufacture and, in particular, to control of cigarette manufacture at the cigarette maker.
In cigarette manufacture, it is customary to condition the tobacco during the primary processing thereof. As part of this conditioning, the tobacco is subjected to procedures wherein the tobacco moisture content is measured, and the measured moisture content is used to control drying or moistening apparatus to achieve a predetermined moisture content. Procedures of this type are disclosed in U.S. Pat. Nos. 3,840,025, 3,482,162, and 3,502,085.
After primary processing, the tobacco is usually stored for a period of time, which may be up to three days, before being made into cigarettes by a cigarette maker. In conventional practice, the storage areas are subjected to a controlled climate in order to maintain the tobacco moisture content at the predetermined level established during the primary processing. Despite such costly storage procedures, the tobacco may still undergo moisture changes while being transported to the cigarette maker. These moisture changes adversely affect maker operation, particularly in cases where the maker is provided with controls for establishing preselected values for various cigarette rod parameters such as rod density and rod firmness. This is mentioned in British Specification No. 1,376,747, which discloses a microwave system for controlling tobacco rod density. In this system, since the microwave energy is affected by moisture as well as by tobacco content, the system is constructed to permit obtaining values of each of these parameters from microwave signals which depend on both.